Most growers use propane C02 generators to boost growth. There is small irony in the sense that most people that I know who use MJ recreationally are also believers in human caused climate change.
I was all for legalization. And still am, yet in the past 20 years there has been an arms race in increasing the potency so that the weed of today bares little resemblance to the mild stuff I use to smoke as a teenager. Personally, can't stand the stuff now and won't let guests at our hosted parties use it, even if its legal. Its too powerful to let a guest drive home. In a way, I think the potency should be stepped down, and legally defined to a certain limit of THC per gram.
The OP says that in his situation a "Cartle" came to town and ran up the price of land on an adjoining farm/property and suggested that the labor was imported and housed on site. That's not how it happens in Oregon. The Growers are usually separate from the Property Owners. The Property Owners just lease the land. Growers put in all the infrastructure and take care of the local labor and the operational costs. The Growers are professional management companies, not the typical Hollywood, outlaw, villains.
We have a land class called F2. It gives a huge break, property tax wise, for lands set aside for trees and other Ag stuff. People would usually use this to grow X-mas trees. And this is where the pot farms all got started: rather quickly. So much so, that there is an excess of Pot production and some of the farms are going in the red. The land owner wins, and the grower loses, cause the lease still holds if its a long term lease.
Legalizing production, on the state level, I would have to say, civilized the industry. Before that, there were many illegal plots established in the National Forests around here. And those were foreign nationals, Cartels, that didn't follow any rules of law. They have almost entirely been eliminated by the Above Board, follow the rules, Grower companies.